The present invention concerns a door frame, especially but not exclusively meant for fireproof doors, said door frame covering the edge sides of a door opening in a wall and consisting of two frame portions assembled from plate profiles bent substantially in L-form, said frame portions being mounted in said door opening in such a way that one leg of each plate profile engages the outside of said wall round said door opening and the other profile leg thereof extends into said door opening substantially parallel with the edge side thereof and overlaps the corresponding profile leg of the other frame portion inside of said door opening.
A number of different ways and means for the mounting of door frames of this kind have already been suggested. It is thus already known to provide one of the frame portions with tabs protruding into the door opening and being nailed fast against the edge side thereof during the mounting. The other frame portion is thereafter usually joined to the frame portion attached in the door opening by means of rivets which are inserted through holes provided during the mounting, or through a pair of holes, which are aligned with each other during the mounting. It is also known to arrange a toothed projection on one of the frame portions, which during the mounting is brought into engagement with a fastening member of the other frame portion to retain said frame portions at a distance from each other determined by the thickness of said wall.
Another prior art device is shown in U.S. Pat. No. 1,180,726. In such a device, two frame members are drawn together by a threaded rod connection, however, the cooperating portions of the threaded rod connection are telescoped together. This provides positive guiding of the frame members, and they therefore cannot adapt to deviations in the parallelism of the outer surfaces of the wall to which they are to be attached. Also, no overlap is provided between the legs extending into the door opening, but merely an overlap between a door abutment surface attached to one leg and the other leg, the other leg also having no portion of the threaded rod connection formed inwardly thereof for preventing damage thereto upon inward movement thereof (toward the wall). Thus it will be seen that the door frame according to the present invention does not have many of the disadvantages of the prior art structures, such as being relatively expensive and/or not being able to adapt to deviations in wall surface parallelism, etc.
It is the primary object of the present invention to provide an improved door frame construction, especially for fireproof doors. This and other objects of the invention will become clear from an inspection of the detailed description of the invention and from the appended claims.